This invention relates generally to video compression and decompression.
Video images may be compressed so that they may be transmitted in a more compact, bandwidth efficient fashion. Generally, techniques for compression involve motion compensation.
In order to compress video, an algorithm examines a sequence of image frames to measure the difference from frame to frame in order to send motion vector information. The motion vector locates a block in a reference frame relative to a block being coded or decoded. Motion compensation is interframe coding that uses such an algorithm that makes use of redundancy between adjacent video frames.
Because motion compensation requires access to a large amount of data, frequent accesses to system memory may be required. The greater the requirements for system memory access, the higher the burden placed by the video compression and decompression apparatus on the host system. In addition, accessing external memory, like system memory, increases the bandwidth requirements of the video compression and decompression apparatus.